Reclosable pouches or bags come in many forms. Some are sold empty, such as for storing leftover food and the like. Others are filled with bulk materials, such as pet foods, granular, liquid or powdered foods for human consumption, or other pourable materials. Even grated cheese products are now packaged in reclosable pouches.
Pouches or bags are typically fashioned from lightweight, flexible material, such as plastic film. The film is folded and joined to form a pouch or bag defining an interior space, and a reclosable fastener is provided at the opening, for holding the pouch closed after removal of some of the contents. Examples of such closures include the common rib-and-groove closures sometimes sold under then mark ZIP-LOC, and hook-and-loop closures sometimes sold under the mark VELCRO. Yet another type of refastenable strip-form closure that has had some use on pouches features mating arrays of discrete, interlocking stems or fastening elements.
Some flat pouches are constructed from a single sheet of plastic film folded at the end of the bag opposite the opening. Some pouches are constructed with side or bottom gussets that expand when the bag is filled. Some bag side gussets may be opened to form pour spouts. Some filled pouches are constructed to stand upright when filled, such as for display on a store shelf.